Equation.io — Claude Code MCP server: graphs as links
Turns equations into interactive 2D and 3D graphs and returns a link that carries the whole graph state. Handy when a formula needs a picture in the reply.
claude mcp add --transport http equation https://equation.io/mcpWhat Equation.io does
The server takes equations, validates the rows and hands back a link to the interactive grapher. Three tools do the work: encode_graph_url builds a link from equations, decode_graph_url parses an existing link back into editable rows, and show_graph renders the grapher inside MCP Apps hosts. Graph state lives in the URL as /g/eq1;eq2, so the address bar is the share mechanism.
The math runs on the site. Expressions compile to GLSL shaders: 2D curves are drawn in a fragment shader, and 3D surfaces appear automatically once z shows up in an equation. The server is stateless over Streamable HTTP, so there is nothing to run locally — just the endpoint https://equation.io/mcp.
These tools are built for an agent rather than a person at a calculator. You can drop the link into a reply, and show_graph will display the graph where the host supports MCP Apps. Everywhere else you get the link and a PNG preview.
What it helps with
- build a shareable link to an interactive graph from a set of equations
- validate equations before rendering and surface a clear error
- decode someone else's graph link back into equations for editing
- show a 3D surface from a formula inside an agent reply
- deliver a graph as an image where interactivity is not supported
Example prompts for the agent
- Graph
y = x^2and give me the link - Make a link to the 3D surface
z = sin(x)cos(y) - Decode this graph link and show me the equations
How to install Equation.io
Platform CLI: remote server
claude mcp add --transport http equation https://equation.io/mcpPlatform CLI: remote server
codex mcp add equationio --url https://equation.io/mcpConfig file
{
"mcpServers": {
"equationio": {
"url": "https://equation.io/mcp"
}
}
}Config file
{
"servers": {
"equationio": {
"type": "http",
"url": "https://equation.io/mcp"
}
}
}Platform CLI: remote server
gemini mcp add -t http equationio https://equation.io/mcpStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Equation.io
How do I install Equation.io in Claude Code?
One command: claude mcp add --transport http equation https://equation.io/mcp. The server is remote, so there is nothing to start locally.
What does Equation.io do?
It builds links to interactive 2D and 3D graphs from equations, decodes those links back, and can render the grapher in hosts that support MCP Apps.
Do I need an API key or a local install?
No. The server is stateless over Streamable HTTP and all computation happens on equation.io.
